LEDs (light-emitting diodes) provide light sources which are energy efficient, and advances in LED technology provide even greater such efficiencies over time. Some typical applications for lighting systems are roadway and parking lot lighting in which there are performance requirements such as the requirement that light be uniformly distributed over areas which are to be lighted while the neighboring regions are to be substantially free of light spillage.
High-luminance light fixtures using LEDs as light source for outdoor applications present particularly challenging problems. High costs due to high complexity becomes a particularly difficult problem when high luminance, reliability, and durability are essential to product success.
Dealing with heat dissipation requirements is still another problem area for high-luminance LED light fixtures. Heat dissipation is difficult in part because high-luminance LED light fixtures typically have many LEDs. Complex structures for LED mounting and heat dissipation have sometimes been deemed necessary, and all of this adds to complexity and cost.
In applications such as retrofitting old HID fixtures and other fixtures with LED light sources, especially decorative luminaries that have a look of a particular architectural style such as “acorn” or “tear drop” light fixtures, it is highly desirable to maintain the overall look of the fixture and old-style appearance of illumination.